This invention particularly relates to poisonous lures for eradication of the common phylum-mollusca(snail and slug) garden pests; and more specifically, the invention relates to those temporary devices which are manually positioned partially into the ground via a downward spike like member.
Heretofore, as revealed via prior art patent-search, it has generally been the practice of inventive thinking to produce poisonous-lures for snails defining a housing structure in which the snail actually enters, and within which the snail even dies, once having partaken of the fatal lure substance. A well known exception to such structural configuration has been in the form of a stake-like poisonous-lure for ant-insects, which was set forth in U.S. Pat. No. 2,547,314(filed August 1944). This shows a vertical light-weight corrugated-metal stake portion, to one side-surface of which is tab-crimped a small circular container filled with a gelatinous substance deadly to ants. The object of this construction was found in the particular undulations which provided tiny pocket areas attractive to the ants, arranged about the perimeter of the poison continer, in addition to a central entry-hole of about 5/16"-diameter. These devices are still a popular selling ant-lure, but are not known to be effective against snails in that they do not afford an attractive cool crevice in which to dwell.
The oldest known device known to employ a spike for retention into the ground is that of U.S. Pat. No. 1,729,389(filed April, 1928), comprising a poison container-cup having an underside spike, and a life-off cap thereupon; allowing filling of the poison into the cup. Still other inventions more specific to snail control are known, for example old U.S. Pat. No. 1,872,780(filed November, 1920) shows a dish-like base over which is positioned a special cover portion having several entryway arches. Another example of a spiked type of snail lure, is found in U.S. Pat. No. 2,239,937(filed January 1939). Which is a three-piece apparatus called a "bait protector", wherein a long rod-like spike with a loop on its uppermost end, is equipped with an annular hood and is inserted down through the center of a bait-dish and down into the ground. This apparatus would thus be to bulky to use in many desired applications, where a dish and overhanging hood could not fit, such as in a flower-pot.
Later, U.S. Pat. No. 2,837,861(filed July, 1957) introduced a spiked insecticide-container having an integral annular tray and a dome-like top having many tiny holes for entry of ants. Again the annular shape would tend to be rather bulky. And U.S. Pat. No. 3,427,743(filed February, 1969) introduced another spike type insect bait-despenser with annularly-compartmented tray, but which uppermost hood member fits down to the ground, while an uppermost installation T-handle is unscrewable from the central spike so as to prevent the installed device from being readily accessed by children and pets. Again though, this configuration is to bulky for use in flower-pots for example.
Then U.S. Pat. No. 3,772,820(filed November, 1973) featured central ground-spike with an annular dome-like hood having a scalloped-rim portion positioned upon the ground, thereby enabling snails and slugs to enter the hood overlying confines. A vertically adjustable portion of the hood may be raised to allow more water to enter from some lawn-sprinkler, thereby metering water therein to activate the poison-bait. Again, the device is to bulky in diameter. U.S. Pat. No. 3,978,607(filed September, 1976) again featured a bait-dish located beneath a perimeter-scalloped hood member, with a central spike passing down unitingly through the aggregate members and into the ground; including a convenient grasping member, enabling the device to be easily withdrawn from the ground for relocation. But again, the device is too bulky for flower-pot use.
Next U.S. Pat. No. 4,485,582(filed December, 1984) shows an insect lethal-feeding station, rather mushroom like in formation; including a tubular ground-spike member for thrusting into the earth. The spike is formed integrally with an upper tray-like bait holding portion, which is topped with a transparent-cap having three perimeter entry apertures Thus, while the device could be installed in a flower-pot, it's structural provisions appear to accommodate use for bugs and ants only.
Finally, U.S. Pat. No. 4,821,452(filed December, 1987) shows a one-piece dome shaped snail-lure, the perimeter of which features three snail entry arches, the sides of which extend downward in a V-shaped manner so that the dome may be easily stabilized an inch or two into the ground by these three prongs. Once having entered the shady confines of the dome, the snail is enticed to climb the inside wall surface between the arches, so as to access the lure of a poison-bait gell-substance applied to the ceiling of the dome chamber. While, the poison is protected from sprinkling water, and not accessible to child or pet while the device is implanted, it is again to bulky to be installed into a flower-pot.
Thus, one can see from this most relevant known invention-art, that there is still room for improvement in devising a ground anchored poison-station, which can be lethal to snails, yet readily installed into a flower-pot.